clinohedrite

{{Infobox mineral | name = Clinohedrite | category = Silicate mineral | image = Clinohedrite1.jpg | imagesize = 260px | caption = Clinohedrite coating hardystonite, franklinite with willemite reaction rims. Franklin, New Jersey. Orange fluorescence under UV. | formula = CaZn(SiO4)·H2O | IMAsymbol=Cnh | strunz = 9.AE.30 | dana = 52.2.1.2 | system = Monoclinic | class = Domatic (m) (same H-M symbol) | symmetry = Cc | unit cell = a = 5.09 Å, b = 15.82 Å, c = 5.38 Å; β = 103.39°; Z = 4 | color = Colorless to brown surface coating, clear to pale pink to amethystine crystals | habit = Thin to thick or platey surface and fracture coatings, in vugs or cavities, rarely as crusts of crystals – prismatic to tabular, may be wedge-shaped | cleavage = Perfect on {010} | mohs = 5.5 | luster = Brilliant, glassy; pearly on {010} | diaphaneity = Transparent to translucent | streak = white | gravity = 3.28–3.33 | opticalprop = Biaxial (−) | refractive = nα = 1.662 nβ = 1.667 nγ = 1.669 | fluorescence = UV=orange | other = Strongly pyroelectric | references = }} Clinohedrite is a rare silicate mineral. Its chemical composition is a hydrous calcium-zinc silicate; CaZn(SiO4)·H2O. It crystallizes in the monoclinic system and typically occurs as veinlets and fracture coatings. It is commonly colorless, white to pale amethyst in color. It has perfect cleavage and the crystalline habit has a brilliant luster. It has a Mohs hardness of 5.5 and a specific gravity of 3.28–3.33.

Under short wave ultraviolet light it fluoresces a rich orange color. It is frequently associated with minerals such as hardystonite (fluoresces violet blue), esperite (fluoresces bright yellow), calcite (fluoresces orange-red), franklinite (non-fluorescent) and willemite (fluoresces green).